You can do anything you want in the Underground

You fall down Mt. Ebbot, you land on a bed of golden flowers. You get up and walk through the big door, you see a big open room, a patch of grass. And a golden flower with a scratchy high pitched voice

Flowey: Howdy, I'm Flowey. Flowey the flower, you're new to the Underground, aren't cha'. Golly, you must be so confused. Guess someone should teach you how things work around here. Guess little old me will have to do.